1. Field of the Invention
The present invention relates to a head protection airbag apparatus that includes an airbag which is folded and accommodated on the upper edge side of the interior side of a window, and to attach the upper edge side at the time of a full inflation to the body side of a vehicle, in which the lower edge side of the airbag at the time of the full inflation is positioned lower than a belt line that is composed of the lower edge of the window.
2. Description of Related Art
In the related art, there is a head protection airbag apparatus that has a configuration disclosed in JP-A-2004-114829. In the head protection airbag apparatus of the related art, an airbag is folded by roll-folding to be wound from the lower edge side thereof toward the exterior side, and is accommodated on the upper edge side of a window. The roll-folding of the airbag is released in sequence, inflation is performed by an inflow of an inflation gas into the inside thereof, and the airbag is unfolded and deployed along the interior side of the window. Therefore, even when a gap between the window and an occupant's head is narrow, it is possible for the airbag to be smoothly inflated to enter the narrow gap.
However, when such a configuration is applied to an airbag that has a configuration in which the lower edge side of the fully inflated airbag is positioned lower than a belt line which is composed of the lower edge of the window, a problem arises as follows. The lower edge side of the fully inflated airbag is positioned lower than the belt line such that the holding performance for the occupant's head is secured even in a rollover. In a case of the airbag having such a configuration, when the roll-folding of the airbag is released and the airbag is deployed, the lower edge side portion interferes with a member, such as a door trim that constitutes the belt line and protrudes to the interior side from the window. Thus, it is not possible for the airbag to be smoothly inflated in some cases.